Researchers develop what they call 'erasable paper'

PALO ALTO, Calif. -- A local invention could fulfill the dreams of every ecologically-minded paralegal.

Scientists at Xerox research centers in Palo Alto and Toronto, Canada, recently announced that they have developed preliminary technology to print pages on which text disappears after 16 hours.

The "erasable paper" relies on chemicals that change color when exposed to a printer's light and then gradually disappear in 16 to 24 hours. Xerox spokesman Bill McKee said the paper can be re-used between 20 and 50 times.

"A lot of people print out their e-mails or daily schedules. They feel guilty about doing that, but not guilty enough to stop," said Eric Shrader, the project's principal researcher at the Palo Alto Research Center.

Shrader said work began on the project after researchers realized the concept of improved "electronic paper" left people unsatisfied.

"What people really want is an enhanced paper product ... the idea is you can do all the things you normally do like organizing in piles and putting the high-priority stuff on top ... while feeling good about not killing trees," he said.

The Palo Alto lab worked on developing the prototype printer with a unique light bar that provides a specific wavelength of light to create the image. The Xerox Research Centre of Canada focused on the chemistry of the special paper.

"In erasable paper, you're not putting anything on the paper," said McKee. "Instead, you're activating chemicals within the paper through a light source."

The text can be erased immediately if exposed to heat or re-printed, he said.

In addition to its wide-ranging office use, Shrader said groups like lawyers have already come up with specific security benefits for paper whose text disappears rapidly.

The paper is still in the development phase and will likely spend three more years in the labs before coming out on the market, McKee said.